Incandescent lamp having a filament surrounded by a wire screen



July 22, 1969 A P. P. HINSSEN ET AL 3,457,449

INCANDE ZSCENT LAMP HAVING A FILAMENT SURROUNDED BY A WIRE SCREEN Filed April 27, 1967 INVENTOR. ANDREAS P. P. HINSSEN THEODORUS J. H .SMEELEN BY AGENT United States Patent 3,457,449 INCANDESCENT LAMP HAVING A FILAMENT SURROUNDED BY A WIRE SCREEN Andreas Petrus Paulus Hinssen and Theodorus Johannes Henricus Smeelen, Emmasingel, Eindhoven, Netherlands, assignors, by mesne assignments, to US. Philips Corporation, New York, N.Y., a corporation of Delaware Filed Apr. 27, 1967, Ser. No. 634,372 Int. Cl. H01k 1/26 U.S. Cl. 313-240 3 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to an incandescent lamp having a filament surrounded by a screen of wire material. The wire is wound generally helically, is secured to stay wires and will minimize the degree of blackening of the interior of the lamp bulb during its operation.

In the prior art such screens were used only in special kinds of lamps, and the construction of these screens was such that their manufacture could not be readily mechanized. This had a detrimental effect on the cost price of such a screen.

It has been found, however, that the field of use of this kind of screen is wider than was originally assumed and there is now a need for a simple screen constructed wherein component screen parts forming a basic shape may be slightly displaced with respect to their supports, to obtain a screen which has a configuration fully satisfying the requirements imposed and which, for example, surrounds the filament substantially completely on all sides.

For this purpose, the incandescent lamp according to the present invention is characterized in that the relevant screen consists of wire material helically wound on one or more stay wires, each of the Wire turns being secured on the stay wires and the screen thus obtained being supported by one or more of the current-supply wires of the filament.

In an advantageous embodiment of the incandescent lamp according to the invention, the wire turns of the screen are bent away from each other to a substantially bulb-shaped configuration surrounding the filament.

In order to obtain such a screen construction, wire material can be helically wound on a winding machine around one or more parallel stay wires and the wire turns can be welded to the stay wires at the areas at which they pass these wires. This technique substantially corresponds with a winding technique used for manufacturing grids for radio valves. Parts having the prescribed length can then each time be cut from the product thus obtained and can be secured on the terminal wires already provided with a filament. If desired, the wire turns may then be bent with the aid of a pair of pincers to the configuration which is most favourable for the object aimed at.

3,457,449 Patented July 22, 1969 In general, the wire material Wound around the stay wires will be chosen to be very thin, for example, of the order 40 1 to This wire material may suitably be constituted by molybdenum or tantalum wire.

The invention will be described with reference to the perspective view of the drawing. According to the invention the part of an incandescent lamp shown comprises the screen, the filament surrounded by the screen, and the terminal wires to which the screen and the filament are secured. For the sake of clarity, other parts of this invention, such as the bulb and the cap, have been omitted.

The filament 1 is secured by its end, 2 to terminal wires 3. A screen 4 surrounding the filament 1 includes the stay wires 5 and 6 around which each of the wire turns of the wire material 7 is helically wound, thereby forming the screen which is secured at areas 8. In the mbodiment shown, the turns of the wire material 7 are bent away from each other to a bulb-shaped configuration, and the stay wire 6 is welded to a terminal wire 3.

The drawing shows only one embodiment of the invention. It will be appreciated that several modifications are possible.

What is claimed is:

1. In an incandescent lamp, a pair of current supply wires, a filament secured to said current supply wires, 8. screen constituted of wire material, a pair of spaced stay wires, said wire material of the screen being helically wound on said stay wires and each of the wire turns being secured to said stay wires, and the screen being supported by at least one of said current supply wires which has at least one of said stay wires mounted thereon.

2. In an incandescent lamp as claimed in claim 1 wherein the wire turns of said screen are bent away from each other to form a substantially bulb-shaped configuration surrounding the filament.

3. In an incandescent lamp as claimed in claim 1 wherein said wire material has a diameter of between 40 and 100a.

References Cited UNITED STATES PATENTS 1,899,587 2/1933 Quesseque 313-42 2,100,879 11/1937 Smith 313-240 X 2,232,816 2/1941 Van Horn 313-42 2,300,997 11/l942 Van Horn 313-240 X 2,326,419 8/1943 Van Horn 313-33 2,467,710 4/ 1949 Van Horn et al. 313-240 X 2,862,125 11/1958 Biggs et al. 313-38 2,973,443 2/ 1961 Wiley 313-42 3,034,007 5/1962 Chaiten 313-38 3,184,629 5/1965 Van Tijen et al. 313-348 X JOHN W. HUCKERT, Primary Examiner r J. R. SHEWMAKER, Assistant Examiner 0 US. Cl.-X.R.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,457 ,449 Dated July 22 1969 Inventor(shNDREAS PETRUS PAULUS HINSSEN -THEODORUS JOHANNES HENRICUE EMEELEN It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, after Filed Apr. 27,1967, Ser. No. 634,372

the next line should read as follows:

--Claims priority application Netherlands June 3,196t

Signed and sealed this 11th day of August 1970.

(SEAL) Attest:

WHLIAM E- 80m, JR. Edwaramnmh c omissioner of Patents Attestingm 

